Personalised AES encryption

p0001It is known that the National Institute of Standards and Technology (NIST), has selected after a worldwide competition for 2001, a symmetric encryption method called Advanced Encryption Standard (AES) as standard (FIPS 197). AES has been designed for worldwide applications in the fields of banking, industry, economy, etc.. The structure of the AES is known and analyzed in the literature. AES fulfills versatile requirements and is effectively implemented on different technological platforms. AES provides a ansehbare security. There have been published various forms of AES implementation.

p0002The general form of the AES involves certain cryptographic hazards. On the one hand it is necessary for many applications, algorithmically sure to separate different application clusters apart. On the other hand, it is useful to obtain the many benefits of AES as upright as possible.

p0003As a solution for specific purposes, a variant of the AES is very beneficial. This version contains only minor changes to AES, for example, is changed, only the round key generation.

p0004Personalization by changing key generators could be performed in different ways. For all forms of implementation, the personalization key is part of the algorithm and is not changed.

implementation Examples

p0005One of the ways to encrypt before AES round key generation data encryption key with an AES in ECB mode and leave the round key generator unchanged (see <figref idrefs="f0001">illustration 1</figref>). In this case, the personalization key is the one key that is associated with this encryption key. The length of both the data encryption key and the personalization key is free to choose.

p0006Another possibility of personalization shows the <figref idrefs="f0002">Figure 2</figref> and the <figref idrefs="f0003">Figure 3</figref> , In this case, the length of the data encryption key 128 or 256 bits, the length of the personalization key is 128 bits. The key encryption is performed using AES in OFB mode.

p0007There are many other possibilities are conceivable to personalize the round key generation with a personalization key for different user groups.